1. Field of the Invention
This invention relates in general to a speaker and to a speaker system, used as an acoustic output means in an acoustic system such as an audio-video system or multi-media system, and in particular to a speaker and a speaker system in which an imaginary ground point is formed in a case.
2. Discussion of Relevant Art
In general, a speaker used as an acoustic output means in an audio-video system or multi-media system comprises a main speaker part for generating sound, and a case for containing and holding the main speaker part inside. The case has a function for containing and holding the main speaker part, and for emitting the sound forward produced by the main part. It also has a function to protect the main speaker part from external force or dust to prevent mechanical or chemical damage.
In a traditional speaker of the prior art, a peripheral portion of a frame in the front side of the main part is fixed to a peripheral portion of the case surrounding a hole formed in the case, to allow the main part to be suspended in midair without any other suspending means.
If a vibration produced by the main part is allowed to transmit to the case, an undesired sound will be excited at a frequency of resonance of the case, to cause a degradation of the quality of sound radiated by the speaker. Such a degradation in the quality of sound is sometimes called a box-sounding. To avoid the box-sounding, it is necessary to prevent a transmission of a vibration from the main speaker part to the case. For this purpose, a countermeasure has been taken in which the peripheral portion of the frame of the main speaker part is attached to the peripheral portion of the case, surrounding the hole, by placing a cushion gasket means, such as foamed plastics, between both peripheral portions, to prevent a transmission of a sound or to attenuate a vibration.
However, the above said countermeasure has not been sufficient to suppress the box-sounding. Therefore, a new countermeasure has been proposed in which the main part is supported by a supporting means placed inside the box without making any contact with the case (Jitsu-kou-show 63-42770, Toku-kai-hei 7-212881). In addition, some devices have been made relating how to attach the main part to such supporting means (Toku-kai-hei 11-289588, Toku-kai-hei 11-355876).
However, the new countermeasure gives restriction to placement of the speaker, because a base of such supporting means must be placed or fixed on a desk or a table outside of the case. Therefore, it is not possible to suspend such a speaker in midair, or to attach such a speaker to a side wall of a case of various electronic components, such as a personal computer.
Accordingly, it is an object of the present invention to provide a speaker and a speaker system which is substantially free from box-sounding.
It is another object of the present invention to provide a new speaker system which has flexibility of placement.
These and other objects of the present invention are achieved by the speaker system of the present invention, as will be understood by a review of the following detailed description section.